The truck overturned at around midday causing traffic snarl-up on the busy highway which crippled transport for the better part of Sunday.
The authority issued a statement informing motorists of the incident.
“KeNHA would like to alert motorists that the Naivasha-Maimahiu-Rironi Road has been blocked due to an accident that occurred along the highway involving a trailer that was moving towards Mai Mahiu.
“Police have been on the site of the accident to open up the road, but the traffic snarl-up has taken longer to open up due to overlapping by other vehicles,” read part of the statement.
KeNHA added that traffic police are now fully in control with the snarl-up projected to clear before 7 p.m.
Motorists were advised to exercise patience as normal traffic was being restored along the highway that connects Narok and Naivasha.
The trailer overturned near the Limuru-Mai Mahiu junction with a video emerging showing residents gathered around the truck.
The accident left many motorists stranded as transport was paralysed the whole afternoon with some seeking alternative routes.
The truck was transporting ballast. The cause of the accident is yet to be established with no casualties reported at the time of writing.